Antennas in particular in the form of stationary mobile radio antennas have been known for a long time.
By way of example, EP 1 082 781 B1 discloses an antenna array having two or more primary antenna element modules which are arranged vertically one above the other and transmit and receive in one position, for example with a vertical alignment. Each individual antenna element may in this case comprise dipole antenna elements or dipole antenna element arrangements.
In addition, antennas, in particular in the form of antenna arrays, are also known which transmit and/or receive on two mutually orthogonal polarization planes. Dual-polarized antennas such as these are known, for example, from DE 198 60 121 A1. In this case, the two mutually perpendicular polarization planes are preferably rotated at an angle of 45° with respect to the horizontal (or vertical). The expression so-called X polarization or X alignment of the antenna elements is also frequently used in this case.
These antennas or antenna arrays likewise once again preferably use dipole antenna elements, for example cruciform dipole antenna elements or else dipole squares. In addition, so-called vector dipoles may also be used, such as those which are known, in principle, from DE 198 60 121 A1. These dipole structures represent a dual-polarized antenna element arrangement which, from the electrical point of view, is constructed in the form of a cruciform dipole and, from the physical point of view, is approximately in the form of a square structure.
Against the background of these fundamentally known antenna elements and antenna element arrangements, the technology herein provides an improved antenna, in particular in the form of an exemplary illustrative non-limiting stationary antenna for a base station for the mobile radio range, which is equipped with a device for carrying out beamforming. An exemplary illustrative non-limiting implementation allows better shaping of far-field polar diagrams to be produced for antennas such as these.
Within the scope of exemplary illustrative non-limiting implementations, it is now possible to specifically improve the shaping of the far-field polar diagrams of corresponding antennas.
In an exemplary illustrative non-limiting implementation, the shaping of the far-field polar diagram may be carried out just for a single antenna element, in particular even if there is only one antenna element emitting one polarization. In the same way, however, the technology herein can also be used for a dual-polarized antenna element or for a dual-polarized antenna element arrangement. The technology herein is not just restricted to a single-band antenna but can also be used and provided for a dual-band antenna or, in general form, for a multiband antenna.
Exemplary illustrative non-limiting implementations are also distinguished in that the desired improvement that has been explained can be achieved by comparatively simple and low-cost measures. Furthermore, the measure that produce the improvement can be used specifically and, in particular, can be associated with individual antenna elements.
In this case, the exemplary illustrative non-limiting measures can be used not just for dual-polarized antennas with dipole antenna elements, but, for example, also for patch antennas. In principle, there are no restrictions on the specific antenna element forms.
The exemplary illustrative non-limiting solution is distinguished, inter alia, by the provision of a passive electrically conductive element, which is conductively connected or capacitively coupled at least indirectly to the electrically conductive reflector.
The exemplary illustrative non-limiting passive electrically conductive element, which is additionally provided at least for one antenna element or one antenna element arrangement, is preferably subdivided into at least two parts and comprises a mounting section, which preferably originates from the reflector and is electrically connected or capacitively coupled to it, and in this case is preferably at least indirectly mechanically connected to the reflector. A so-called operating section, which is preferably arranged on a plane running parallel to the reflector, is then provided on the side of the mounting section facing away from the foot point of the mounting section (which is located in the vicinity of the reflector or of the reflector plane). This operating section may, moreover, be arranged such that it differs from the alignment of the reflector plane at least in an angular range of ±20°, and preferably less than ±10°, that is to say running at an angle to the reflector plane.
The technology herein provides for this operating section to have a length of preferably 0.2λ up to and including 1.0λ, where λ corresponds to the wavelength in the frequency range or frequency band to be transmitted, preferably the mid-wavelength of the frequency range to be transmitted. The operating plane itself may be arranged above or below the antenna element plane of the active antenna element to be influenced by it. There is no restriction to this. However, the length of the mounting section, which is greater than the distance between the operating section of the passive electrically conductive element on the reflector, should not exceed a maximum value corresponding to twice the wavelength mentioned above in one exemplary illustrative implementation.
The material thickness and the transverse dimensions transversely with respect to the extent direction of the electrically conductive additionally provided beamformer element should preferably be less than 0.1 times the operating wavelength, preferably the mid-operating wavelength of the element to be influenced.
In principle, mobile radio antennas which comprise decoupling elements that are in the form of rods and extend essentially at right angles to the reflector plane are known from the prior art, for example also from WO 01/04991 A1. These passive, electrically conductive coupling elements are conductively connected to the reflector plate, or are capacitively coupled at their foot point to the conductive reflector. However, these elements are electrically conductive passive decoupling devices, in order to achieve better decoupling between two dual-polarized antenna elements or antenna element devices.
However, an aim of the exemplary illustrative non-limiting implementation herein is not merely to ensure a decoupling element for improvement of the decoupling between two dual-polarized emission planes but, instead, an aim is to change and to shape the polar diagram in a desired manner, for example even in the case of an antenna element device which emits only a single polarization plane, particularly when viewed in the far field. The technology herein therefore also provides for the operating section of the exemplary illustrative non-limiting electrically conductive beamforming element to run such that it is aligned at least essentially or approximately on the operating plane mentioned above, which is preferably parallel to the reflector plane, in the polarization direction of the element to be influenced. In an exemplary illustrative non-limiting implementation, discrepancies of preferably less than 20% and in particular of less than 10%, can also still bring about the desired success.